It should have no effect on fertilizer or phosphate prices, because it is a cheaper method to produce certain organic compounds of phosphorus.
Phosphate is used as an input for these chemical processes, but the fraction of the phosphate production that is used for such processes is very small in comparison with what goes into fertilizers.
The only possible effect is a price reduction for some organic compounds of phosphorus, e.g. for some pesticides.
I don't know about costs but phosphorus is a limited resource and more than 70 percent of the world's supply of phosphates is controlled by one country: Morocco.
Some estimates put "Peak Phosphorus" as early as 2030 but unsurprisingly, that claim is highly contested.
Phosphate is used as an input for these chemical processes, but the fraction of the phosphate production that is used for such processes is very small in comparison with what goes into fertilizers.
The only possible effect is a price reduction for some organic compounds of phosphorus, e.g. for some pesticides.